The present invention relates to power divider/combiners and more particularly to improved microwave radio frequency power divider/combiners.
The in-line, or Wilkinson-type power divider/combiner has proved very useful for in-phase, equal or unequal power division and combining for applications having moderate power levels or a frequency range where the series resistors can be made sufficiently large to dissipate reasonable power levels. The design criteria and characteristics have been well documented, and because of its electrical and mechanical symmetry, its performance over moderate bandwidths has been superior to other types of couplers, such as rat races and branch arm dividers. At higher frequencies or higher power levels, however, there has been great difficulty in building extremely accurate in-phase high power power divider/combiners because of the physical limitations of the resistors needed for the Wilkinson circuit. These resistors must be physically small and it is difficult to heat sink them because of the additional shunt capacity which has the effect of degrading the performance. In 1975, Ulrich H. Gysel published a paper entitled "A New N-Way Power Divider/Combiner Suitable For High Power Applications", 1975 IEEE-MTTS, Int'l. M. W. Symposium Digest, pages 116-118. While the Gysel network or power divider/combiner does provide a higher power solution for the Wilkinson-type power divider/combiner, the Gysel network can not be realized in a single planar design for N greater than two.